Roughly half of businesses that buy search ads directly from Google and other Internet search companies don't come back the following year, but there are ways to curb that trend, according to a study released Monday from Borrell Associates and Clickable. Many online advertising resellers and affiliates, who serve local businesses, churn half their customers within a year. Some lose as many as 90%. The report suggests that missed expectations and a lack of return on investment (ROI) for local-business customers contribute to the change. The churn rate for ReachLocal, LookSmart and Yodle -- companies that purchase search ads on behalf of local advertisers -- is around 60% annually.
